2 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
8 * This file is released under the GPLv2.
11 #include <linux/string.h>
12 #include <linux/delay.h>
13 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/console.h>
16 #include <linux/cpu.h>
17 #include <linux/syscalls.h>
18 #include <linux/gfp.h>
20 #include <linux/kernel.h>
21 #include <linux/list.h>
23 #include <linux/slab.h>
24 #include <linux/suspend.h>
28 const char *const pm_states[PM_SUSPEND_MAX] = {
29 [PM_SUSPEND_STANDBY] = "standby",
30 [PM_SUSPEND_MEM] = "mem",
33 static struct platform_suspend_ops *suspend_ops;
36 * suspend_set_ops - Set the global suspend method table.
37 * @ops: Pointer to ops structure.
39 void suspend_set_ops(struct platform_suspend_ops *ops)
41 mutex_lock(&pm_mutex);
43 mutex_unlock(&pm_mutex);
46 bool valid_state(suspend_state_t state)
49 * All states need lowlevel support and need to be valid to the lowlevel
50 * implementation, no valid callback implies that none are valid.
52 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
56 * suspend_valid_only_mem - generic memory-only valid callback
58 * Platform drivers that implement mem suspend only and only need
59 * to check for that in their .valid callback can use this instead
60 * of rolling their own .valid callback.
62 int suspend_valid_only_mem(suspend_state_t state)
64 return state == PM_SUSPEND_MEM;
67 static int suspend_test(int level)
69 #ifdef CONFIG_PM_DEBUG
70 if (pm_test_level == level) {
71 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
75 #endif /* !CONFIG_PM_DEBUG */
80 * suspend_prepare - Do prep work before entering low-power state.
82 * This is common code that is called for each state that we're entering.
83 * Run suspend notifiers, allocate a console and stop all processes.
85 static int suspend_prepare(void)
89 if (!suspend_ops || !suspend_ops->enter)
94 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
98 error = usermodehelper_disable();
102 error = suspend_freeze_processes();
106 suspend_thaw_processes();
107 usermodehelper_enable();
109 pm_notifier_call_chain(PM_POST_SUSPEND);
110 pm_restore_console();
114 /* default implementation */
115 void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
120 /* default implementation */
121 void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
127 * suspend_enter - enter the desired system sleep state.
128 * @state: state to enter
130 * This function should be called after devices have been suspended.
132 static int suspend_enter(suspend_state_t state)
136 if (suspend_ops->prepare) {
137 error = suspend_ops->prepare();
139 goto Platform_finish;
142 error = dpm_suspend_noirq(PMSG_SUSPEND);
144 printk(KERN_ERR "PM: Some devices failed to power down\n");
145 goto Platform_finish;
148 if (suspend_ops->prepare_late) {
149 error = suspend_ops->prepare_late();
154 if (suspend_test(TEST_PLATFORM))
157 error = disable_nonboot_cpus();
158 if (error || suspend_test(TEST_CPUS))
161 arch_suspend_disable_irqs();
162 BUG_ON(!irqs_disabled());
164 error = sysdev_suspend(PMSG_SUSPEND);
166 if (!suspend_test(TEST_CORE) && pm_check_wakeup_events()) {
167 error = suspend_ops->enter(state);
168 events_check_enabled = false;
173 arch_suspend_enable_irqs();
174 BUG_ON(irqs_disabled());
177 enable_nonboot_cpus();
180 if (suspend_ops->wake)
183 dpm_resume_noirq(PMSG_RESUME);
186 if (suspend_ops->finish)
187 suspend_ops->finish();
193 * suspend_devices_and_enter - suspend devices and enter the desired system
195 * @state: state to enter
197 int suspend_devices_and_enter(suspend_state_t state)
204 if (suspend_ops->begin) {
205 error = suspend_ops->begin(state);
210 pm_restrict_gfp_mask();
211 suspend_test_start();
212 error = dpm_suspend_start(PMSG_SUSPEND);
214 printk(KERN_ERR "PM: Some devices failed to suspend\n");
215 goto Recover_platform;
217 suspend_test_finish("suspend devices");
218 if (suspend_test(TEST_DEVICES))
219 goto Recover_platform;
221 suspend_enter(state);
224 suspend_test_start();
225 dpm_resume_end(PMSG_RESUME);
226 suspend_test_finish("resume devices");
227 pm_restore_gfp_mask();
230 if (suspend_ops->end)
235 if (suspend_ops->recover)
236 suspend_ops->recover();
241 * suspend_finish - Do final work before exiting suspend sequence.
243 * Call platform code to clean up, restart processes, and free the
244 * console that we've allocated. This is not called for suspend-to-disk.
246 static void suspend_finish(void)
248 suspend_thaw_processes();
249 usermodehelper_enable();
250 pm_notifier_call_chain(PM_POST_SUSPEND);
251 pm_restore_console();
255 * enter_state - Do common work of entering low-power state.
256 * @state: pm_state structure for state we're entering.
258 * Make sure we're the only ones trying to enter a sleep state. Fail
259 * if someone has beat us to it, since we don't want anything weird to
260 * happen when we wake up.
261 * Then, do the setup for suspend, enter the state, and cleaup (after
264 int enter_state(suspend_state_t state)
268 if (!valid_state(state))
271 if (!mutex_trylock(&pm_mutex))
274 printk(KERN_INFO "PM: Syncing filesystems ... ");
278 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
279 error = suspend_prepare();
283 if (suspend_test(TEST_FREEZER))
286 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
287 error = suspend_devices_and_enter(state);
290 pr_debug("PM: Finishing wakeup.\n");
293 mutex_unlock(&pm_mutex);
298 * pm_suspend - Externally visible function for suspending system.
299 * @state: Enumerated value of state to enter.
301 * Determine whether or not value is within range, get state
302 * structure, and enter (above).
304 int pm_suspend(suspend_state_t state)
306 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
307 return enter_state(state);
310 EXPORT_SYMBOL(pm_suspend);